CN102283665A

CN102283665A - Nuclear medicine imaging apparatus, and nuclear medicine imaging method

Info

Publication number: CN102283665A
Application number: CN201110162952XA
Authority: CN
Inventors: 森安健太; 本村信笃
Original assignee: Toshiba Corp; Toshiba Medical Systems Corp
Current assignee: Toshiba Corp; Canon Medical Systems Corp
Priority date: 2010-06-17
Filing date: 2011-06-17
Publication date: 2011-12-21
Also published as: US20110309252A1; CN102973290A; CN102973290B; US9029786B2

Abstract

The invention provides a nuclear medicine imaging apparatus, and a nuclear medicine imaging method. According to one embodiment, a PET apparatus includes a detector, a calibrator (24), and an image reconstruction unit (25). The detector includes a plurality of detector modules (14), each counting light originating from a gamma ray. The calibrator unit calibrates time information of all of the plurality of detector modules (14) by calibrating time information for determining each detection time of a pair of detector modules (14) based on each detection time of the pair of the detector modules which approximately coincidentally count annihilation gamma rays and a distance between the pair of detector modules (14) in a state in which a point radiation source including a positron emitting nuclide is installed in each position near a plurality of predetermined detector modules (14). The image reconstruction unit (25) reconstructs a PET image of a detected object using a time difference between detection times of annihilation gamma rays corrected based on time information of the plurality of detector modules (14) calibrated by the calibrator (24).

Description

Nuclear medical imaging apparatus and nuclear medicine method

The cross reference of related application

The application requires the priority of Japanese patent application No.2010-138462 formerly that submitted on June 17th, 2010 and the Japanese patent application No.2010-138463 formerly that submitted on June 17th, 2010, and the full content of above-mentioned Japanese patent application is by reference in conjunction with in this application.

Technical field

The present invention relates to nuclear medical imaging apparatus and nuclear medicine method.

Background technology

In the past, as the nuclear medical imaging apparatus of the functional diagnosis of the bio-tissue that can carry out subject, well-known a kind of positron emission CT device (PET device, PET:Positron Emission computed Tomography: positron emission electronic computer tomography).

Concrete condition is, in PET checks, and will be to subject with the medicament delivery of positron emission nucleic sign.And, combine with electronics and when disappearing at positron from medicament radiation, PET device uses the detector of being made up of the detector module that disposes photon counting (photon counting) mode of ring formation (ring) shape around subject to be counted as simultaneously γ (gamma) ray (annihilation gamma ray in pairs), and above-mentioned paired gamma-rays is the ray at the 511keV that roughly launches in the other direction.And PET device is by carrying out calculation process to the gamma-ray data (data) (simultaneously count information) of counting simultaneously, thereby carries out the reconstruction of PET image.

The flight time)-PET device in addition, in recent years, continually developing a kind of difference and correctly determine TOF (the Time Of Flight: of the gamma-ray position of emission detection time of utilizing paired annihilation gamma ray.Because gamma-ray speed is the light velocity, so TOF-PET device desired detection time of difference is hundreds of psec (psec) levels (order).So needing in the TOF-PET device aligns accurately is used to determine the temporal information of the detection time of each detector module (module).

As the method for the temporal information of proofreading and correct each detector module, generally use the method for germanium (germanium) 68 grade point radiation sources.In the method, at the FOV of PET image (Field Of View: set-point radiation source the visual field), and utilize the detector module at two places to detect a paired annihilation gamma ray that produces by a radiation source.And, in the method, according to the detection time of two detector module that detect paired annihilation gamma ray, correction time information.

Summary of the invention

Yet in above-mentioned bearing calibration, the combination that is detected as gamma-ray two detector module of pair annihilation is restricted to the linearity of point of contact radiation source.Therefore, above-mentioned bearing calibration can't be proofreaied and correct the temporal information of all detector module.

The nuclear medical imaging apparatus of embodiment possesses detector, correction unit and image reconstruction portion.Detector has a plurality of detector module of counting from gamma-ray light.Correction unit is according to installing each detection time of two detector module roughly having counted paired annihilation gamma ray under the state that is equipped with the some radiation source that comprises the positron emission nucleic simultaneously and the distance between this two detector module everybody of a plurality of detector module near regulation, correction is used to determine these two detector module temporal information of detection time separately, thereby proofreaies and correct whole temporal information of above-mentioned a plurality of detector module.When the subject of having thrown in the material that is identified by the positron emission nucleic is photographed, image reconstruction portion uses the time difference of each detection time of paired annihilation gamma ray, rebuild the nuclear medical image of above-mentioned subject, above-mentioned paired annihilation gamma ray is the ray of having revised according to by the corrected above-mentioned a plurality of detector module of above-mentioned correction unit temporal informations separately.

To propose other purpose of the present invention and advantage in the following description, partial content can become from the description of description obviously, perhaps can clear and definite foregoing by implementing the present invention.Can realize and obtain objects and advantages of the present invention by means and the combination of hereinafter pointing out in detail.

[invention effect]

According to the nuclear medical imaging apparatus of embodiment, can rebuild accurately and use gamma-ray detection time of poor image.

Description of drawings

The accompanying drawing that is combined in here and constitutes the part of description is described presently preferred embodiments of the invention, and with above-mentioned summary description and following detailed description of the preferred embodiment together is used for illustrating principle of the present invention.

Fig. 1 is the figure of structure that is used for illustrating the PET device of embodiment 1.

Fig. 2 is the figure that is used to illustrate detector module.

Fig. 3 is the figure that is used to illustrate the problem of bearing calibration in the past.

Fig. 4 is the figure that is used for illustrating in the position of embodiment 1 set-point radiation source.

Fig. 5 is used for illustrating the figure that can be detected as the combination of the gamma-ray detector module of pair annihilation at embodiment 1.

Fig. 6 is the figure that is used for illustrating in an example of a plurality of positions of embodiment 1 set-point radiation source.

Fig. 7 is the multiple figure that is used to illustrate the detector module between the recoverable scope of setting by an example shown in Figure 6.

Fig. 8 A and Fig. 8 B are the figure that is used for illustrating the keeper (holder) that the detector cover (cover) of embodiment 1 has.

Fig. 9 is the figure that is used for illustrating the correction unit of embodiment 1.

Figure 10 is the figure that is used for illustrating the time information data of embodiment 1.

Figure 11 is the figure that is used for illustrating the image reconstruction portion of embodiment 1.

Figure 12 is the flow chart (flowchart) that is used for illustrating that the correction of the PET device of embodiment 1 is handled.

Figure 13 is the flow chart of image reconstruction process that is used for illustrating the PET device of embodiment 1.

Figure 14 is the figure that is used to illustrate the variation of recoverable scope.

Figure 15 is the figure of variation of embodiment 1 that is used to illustrate and put the setting of radiation source.

Figure 16 is the figure that is used for illustrating the some radiation source that embodiment 2 uses.

Figure 17 is for being detected as the figure of the combination of the gamma-ray detector module of pair annihilation in embodiment 2.

Figure 18 is the figure that is used for illustrating the correction unit of embodiment 2.

Figure 19 is the figure that is used for illustrating the time information data of embodiment 2.

Figure 20 is the figure that is used for illustrating the image reconstruction portion of embodiment 2.

Figure 21 is the flow chart that is used for illustrating that the correction of the PET device of embodiment 2 is handled.

Figure 22 is the flow chart of image reconstruction process that is used for illustrating the PET device of embodiment 2.

Figure 23 is the figure that is used for illustrating the correction unit of embodiment 3.

Figure 24 is the flow chart that is used for illustrating that the correction of the PET device of embodiment 3 is handled.

Figure 25 A and 25B are the figure that is used to illustrate the variation of embodiment 2 and the 3 point radiation sources that use.

The specific embodiment

Below, will describe as embodiment as PET (the Positron Emission computed Tomography) device of nuclear medical imaging apparatus.

PET device is for by counting a pair of gamma-rays of being thrown in to the tissue emission of the positron emission nucleic of subject from being taken into (annihilation gamma ray in pairs) simultaneously, thereby expresses the device of reconstruction of the PET image of the tissue distribution that is taken into the positron emission nucleic.At this, the PET device in the present embodiment is for (Time Of Flight: the flight time) method is rebuild the device of TOF-PET image, wherein differs from and the gamma-ray position of correctly definite emission the detection time of the paired annihilation gamma ray of TOF method utilization by TOF.

At first, use Fig. 1 that the structure of the PET device among the embodiment 1 is described.Fig. 1 is the figure of structure that is used for illustrating the PET device of embodiment 1.As shown in Figure 1, the PET device of embodiment 1 has pallet device 10 and control station (console) device 20.

Pallet device 10 for during the supervision (monitoring) of regulation to from being devoted in the subject P and optionally being taken into the device that the paired annihilation gamma ray of positron emission nucleic emission of the bio-tissue of subject P is counted, have top board 11, bed (couch) 12, bed drive division 13, detector module 14, detector cover 15, FE circuit 16 and coincidence circuit 17.In addition, as shown in Figure 1, pallet device 10 has the cavity that becomes the shooting mouth.

Top board 11 is the horizontal bed board of subject P, is configured on the bed 12.Bed drive division 13 moves to subject P in the photography mouth of pallet device 10 by moving bed 12 under the control of aftermentioned bed control part 23.

14 pairs of detector module are counted from gamma-ray light.That is, detector module 14 is for detecting from the detector module of gamma-ray photon counting (photon counting) mode of subject P emission, and in pallet device 10, a plurality of detector module 14 for example are configured to surround ring-type around subject P.In addition, a plurality of detector module 14 are not limited to be configured to cyclic situation, for example, also can will be arranged in that a plurality of detector module 14 on the flat board are configured in across two subject P and the situation of relative position.Below, summarizing a plurality of detector module 14 sometimes and recording and narrating simply is detector.That is, detector has a plurality of detector module 14.Fig. 2 is the figure that is used to illustrate detector module.

For example, as shown in Figure 2, detector module 14 is for having flasher (scintillator) 141, photomultiplier tube 142 (PMT:Photomultiplier Tube) and light wave peace lattice type (Anger type) detector to (lightguide) 143.

As shown in Figure 2, flasher 141 two-dimensional arrangements are a plurality of will be by subject P emission and incident gamma-rays is converted to NaI, the BGO etc. of visible light.In addition, photomultiplier tube 142 as shown in Figure 2, disposes a plurality of across fiber waveguide (light guide) 143 for making from the visible light multiplication of flasher 141 outputs and being converted into the device of the signal of telecommunication densely.Fiber waveguide 143 is used for the visible light from flasher 141 outputs is passed to photomultiplier tube 142, by formations such as the good plastics of light transmission (plastic) materials.

In addition, photomultiplier tube 142 produces photoelectronic photocathode, the multistage dynode of the electric field that the photoelectron that is produced is quickened is provided and constitutes as the anode of electron stream outlet by accepting passage of scintillation light.By photoelectric effect from the photocathode electrons emitted quickened towards dynode and with the surface collision of dynode, overflow a plurality of electronics.Because multistage dynode all repeats this phenomenon, thereby doubles like the electron number snowslide, anodic electron number reaches about 1,000,000.In this example, the ratio of profit increase of photomultiplier tube 142 is 1,000,000 times.In addition, applying 600 volts of voltages more than (volt) between dynode and the anode usually in order to utilize snowslide phenomenon to amplify.

Like this, detector module 14 is converted to visible light by flasher 14 with gamma-rays, and the visible light after will changing by photomultiplier tube 142 is converted to the signal of telecommunication, thereby to counting from the gamma-ray quantity of subject P emission.

Be back to Fig. 1, detector cover 15 is for taking in the cover of the detector of being made up of a plurality of detector module 14.In addition, each detector module 14 is received in the module cage, and detector cover 15 is taken in each detector module 14 that is incorporated in the module cage.

FE circuit 16 is connected a plurality of photomultiplier tubes 142 back level separately that a plurality of detector module 14 have separately, and is connected the prime (Front End) of coincidence circuit 17.FE circuit 16 generates the employed various data of processing of coincidence circuit 17 according to the signal of telecommunication of each photomultiplier tube 142 output.

That is, FE circuit 16 waveform shaping of simulation (analog) Wave data of carrying out the signal of telecommunication of each photomultiplier tube 142 outputs is handled.Concrete condition is, FE circuit 16 is by carrying out calculation process (Integral Processing and differential are handled) to the analog waveform data, thereby the generation wave height is the data of energy (energy).

And FE circuit 16 is distinguished gamma-ray incoming position.Concrete condition is, FE circuit 16 is according to the position of the photomultiplier tube 142 that will be converted to the signal of telecommunication and output with same timing from the visible light of flasher 141 outputs and energy and the computing position of centre of gravity, thereby determines gamma-ray incoming position (position of flasher 141).

And FE circuit 16 is according to the analog waveform data of the signal of telecommunication of each photomultiplier tube 142 output, and measurement detects the gamma-ray time (detection time).For example, FE circuit 16 detects the moment that becomes predefined magnitude of voltage threshold value in the analog waveform data and is gamma-ray detection time.

And FE circuit 16 will be exported to coincidence circuit 17 as the count information of detector by the data (gamma-ray detection position, gamma-ray energy value, gamma-ray detection time) that above-mentioned processing generates.

Coincidence circuit 17 is created on the combination of roughly having counted simultaneously from two count informations of the paired annihilation gamma ray of positron emission nucleic emission in the official hour scope from the count information of FE circuit 16 output as the while count information.

Concrete condition is, coincidence circuit 17 is according to the various numerical datas (digital data) from 16 outputs of FE circuit, the gamma-ray incident timing of retrieval (Coincidence Finding) (detection time) all is in the combination in certain energy window (window) scope in the time window scope of certain hour with interior (for example, 2 millimicros (nano) are in second), energy.And the output result of the combination that coincidence circuit 17 will be retrieved generates count information (Coincidence List) simultaneously as roughly having counted the information of paired annihilation gamma ray simultaneously.And coincidence circuit 17 is used the while count information as the PET image reconstruction data for projection sends to control station device 20.At this, the line that links two detection positions of having counted paired annihilation gamma ray simultaneously is called as LOR (Line of Response).In addition, in the present embodiment, the situation of count information is illustrated to generating simultaneously in pallet device 10.But present embodiment is also applicable to generate the situation of count information simultaneously in control station device 20.

Control station device 20 is for accepting the operation of operator to PET device, and according to by pallet device 10 collected the time count information rebuild the device of PET image (being the TOF-PET image in the present embodiment).

Concrete condition is, as shown in Figure 1, control station device 20 has input part 21, display part 22, bed control part 23, correction unit 24, image reconstruction portion 25, data store 26 and system (system) control part 27, and the each several part that control station device 20 is had connects via internal bus (bus).

The operator that input part 21 has PET device imports various indications, the employed mouse of various setting (mouse), keyboard (keyboard) etc., and the indication that will there accept from the operator, the message transport of setting are to systems control division 27.

Display part 22 is the monitor (monitor) of operator institute reference, under the control of systems control division 27, show that to the operator PET image or demonstration are used for accepting from the operator via input part 21 GUI (the Graphical User Interface: graphic user interface) of various indications, various settings etc. there.

Bed control part 23 moves to subject P in the photography mouth of pallet device 10 by control bed drive division 13.

Correction unit 24 is proofreaied and correct and is used to determine detector module 14 temporal information of detection time separately.In addition, at correction unit 24, the back is described in detail.

As shown in Figure 1, data store 26 has count information data 26a, time information data 26b and view data 26c simultaneously.Count information when count information data 26a storage coincidence circuit 17 generates simultaneously.The PET image that view data 26c storage is rebuild by image reconstruction portion 25.The result of time information data 26b storage correction unit 24.In addition, at the content that time information data 26b is stored, the back is described in detail.

Count information (data for projection) when image reconstruction portion 25 reads coincidence circuit 17 and generates from while count information data 26a, and use for example convergence method, thus the data for projection of being read is rebuild the PET image.And the image reconstruction portion 25 in the present embodiment uses the time difference of the detection time of count information simultaneously, rebuilds the TOF-PET image.And image reconstruction portion 25 is stored in the PET image of rebuilding among the view data 26c of data store 26.

Systems control division 27 carries out the integral body control of PET device by the action of control pallet device 10 and control station device 20.Concrete condition is, the collection and treatment of count information in the time of the moving of systems control division 27 control beds 12, FE circuit 16 and coincidence circuit 17.In addition, systems control division 27 is according to the set information from the operator via input part 21 inputs, and control figure is as the reconstruction process of the PET image of reconstruction portion 25.In addition, systems control division 27 is controlled, and makes to show the PET image that control view data 26c is stored on display part 22.

More than, be illustrated at the overall structure of the PET device among the embodiment 1.Under this structure, the PET-CT device of embodiment 1 is rebuild above-mentioned TOF-PET image.

At this, when rebuilding the TOF-PET image, because gamma-ray speed is the light velocity, so the temporal resolution of each detector module 14 of PET device is very important.That is, when rebuilding the TOF-PET image, need to proofread and correct accurately to be used to determine detector module 14 temporal information of detection time separately.

In the past, for information correction time, generally used the method for the some radiation source that comprises germanium 68 nucleic such as positron emission such as grade.In this method (below, record and narrate be previous methods), at the FOV of PET image (Field Of View: set-point radiation source the visual field).For example, a radiation source is arranged on the center of photography mouth.Under this state, coincidence circuit 17 generates count information simultaneously.As mentioned above, simultaneously count information comprises the information of two detector module 14 detection time separately that detects paired annihilation gamma ray.

Previous methods detects the time difference of two detector module 14 detection times separately of paired annihilation gamma ray and the distance that two detector module 14 range points radiation source separately of detecting paired annihilation gamma ray is provided with the position by use, correction time information.Fig. 3 is the figure that is used to illustrate the problem of bearing calibration in the past.

But, as shown in Figure 3, in FOV, be provided with when comprising the some radiation source 30 of positron emission nucleic, can be detected as the pair of detectors module 14 that pair annihilation gamma-ray a pair of (pair) detector module 14 is restricted to the linearity of point of contact radiation source 30 usually.For example, previous methods can't two detector module 14 of surrounding shown in Figure 3 with solid circles each, with 1 detector module 14 of dotted line circle encirclement shown in Figure 3 between be detected as the pair annihilation gamma-rays.Can't the align temporal information of all detector module 14 of its result, previous methods.

Therefore, in the present embodiment,, in taking in the detector cover 15 of detector, the some radiation source 30 that comprises the positron emission nucleic is set in position near a plurality of detector module 14 of stipulating in order to proofread and correct the temporal information of all detector module 14.Fig. 4 is the figure that is used for illustrating in the position of embodiment 1 set-point radiation source.

For example, as shown in Figure 4, in detector cover 15 near set-point, detector module 14-1 ground radiation source 30, by near set-point, detector module 14-1 ground radiation source 30, it is roughly the same to make detector module 14-1 detect the time during with the paired annihilation gamma ray of some radiation source 30 emissions gamma-ray time from a side of the paired annihilation gamma ray of a radiation source 30 emissions.In addition, by near set-point, detector module 14-1 ground radiation source 30, make and incide detector module 14-1 from a side's of the paired annihilation gamma ray of a radiation source 30 emissions gamma-rays great majority (for example, about 70%).Other is that the position near detector module 14 of collocation point radiation source 30 is not limited in the detector cover 15, can be the situation on the detector cover 15 yet.

And, by set-point radiation source as illustrated in fig. 4, in the present embodiment, compare the situation of set-point radiation source 30 in FOV, can increase the combination that can be detected as the gamma-ray detector module 14 of pair annihilation.Fig. 5 is used for illustrating the figure that can be detected as the combination of the gamma-ray detector module of pair annihilation at embodiment 1.

For example, as shown in Figure 5, in embodiment 1, can in detector module 14-1 and detector module 14-17, detect from the paired annihilation gamma ray of a radiation source 30 emissions, and, can in detector module 14-1 and detector module 14-21, detect.That is, in embodiment 1, can proofread and correct the temporal information of a plurality of detector module 14 via detection module 14-1.

At this, as mentioned above, in embodiment 1, at a plurality of different set-point, position radiation source 30 near a plurality of detector module 14 of stipulating.This is because will put the position is set is a place of radiation source 30 time, and the combination of gauged detector module 14 that can carry out temporal information is limited.For example, near set-point, detector module 14-1 ground radiation source 30 time, with the detector module 14 of detector module 14-1 adjacency in paired annihilation gamma ray accuracy of detection since gamma-ray angle of incidence diminish and variation.That is, according to a radiation source 30 the position being set and the recoverable scope of temporal information is limited.For example, the recoverable scope is the scope by setting apart from the angle (solid angle) of the detector module 14 of set-point radiation source 30 closely.

Therefore, in embodiment 1, so that be in according to the detector module in the recoverable scope that set positions is set of a radiation source 30 at least one and the multiple mode of detector module in the recoverable scope of set positions is set according to other of a radiation source 30, adjust a plurality of positions that are provided with of some radiation source 30.Fig. 6 is the figure that is used for illustrating in an example of a plurality of positions of embodiment 1 set-point radiation source.

In an example shown in Figure 6, near each position (4 place) set-point radiation source 30 in 36 detector module 14, detector module 14-1,14-10,14-19 and 14-28.Thus, near set-point, the position radiation source 30 of detector module 14-1 the time, the recoverable scope for example is illustrated in figure 6 as detector module 14-14 to 14-24.In addition, near set-point, the position radiation source 30 of detector module 14-10 the time, the recoverable scope for example is illustrated in figure 6 as detector module 14-23 to 14-33.In addition, near set-point, the position radiation source 30 of detector module 14-19 the time, the recoverable scope for example is illustrated in figure 6 as detector module 14-32 to 14-36 and 14-1 to 14-6.In addition, near set-point, the position radiation source 30 of detector module 14-28 the time, the recoverable scope for example is illustrated in figure 6 as detector module 14-5 to 14-13.Fig. 7 is the multiple figure that is used to illustrate the detector module between the recoverable scope that sets by an example shown in Figure 6.

That is, in an example shown in Figure 6, as shown in Figure 7, and in each recoverable scope of detector module 14-1 and detector module 14-10, these two repetitions of detector module 14-23 and 14-24.In addition, in an example shown in Figure 6, as shown in Figure 7, and in each recoverable scope of detector module 14-10 and detector module 14-19, these two repetitions of detector module 14-32 and 14-33.In addition, in an example shown in Figure 6, as shown in Figure 7, and in each recoverable scope of detector module 14-19 and detector module 14-28, these two repetitions of detector module 14-15 and 14-6.In addition, in an example shown in Figure 6, as shown in Figure 7, and in each recoverable scope of detector module 14-1 and detector module 14-28, these two repetitions of detector module 14-13 and 14-14.

Thus, in embodiment 1, can in all combinations of a plurality of detector module 14, carry out the correction of temporal information.In addition, in Fig. 3 to Fig. 7, for convenience of explanation, the number that shows detector module 14 is 36 a situation.But, in fact also have the situations of hundreds of of the number as many as of the detector module 14 that PET device has.

At this, as mentioned above, will put radiation source 30 and be arranged in the detector cover 15.Therefore, in order to take in a radiation source, the detector cover 15 of embodiment 1 has the keeper shown in Fig. 8 A for example or Fig. 8 B.Fig. 8 A and Fig. 8 B are the figure that is used to illustrate the keeper that the detector cover of embodiment 1 is had.

For example, in an example as shown in Figure 6 during illustrated 4 place set-point radiation source 30, in detector cover 15, shown in 8A, keeper 151,152,153 and 154 is set in each position near detector module 14-1,14-10,14-19 and 14-28.Thus, set-point radiation source 30 closely.

Perhaps, for example shown in Fig. 8 B, in detector cover 15, door leaf 1511 is set in position near detector module 14 (detector module 14-1).And, in the module cage 1512 of taking in detector module 14-1, keeper 151 is set.Similarly, in each position door leaf is set near detector module 14-10,14-19 and 14-28.And, in taking in each the module cage of detector module 14-10,14-19 and 14-28, keeper 152,153 and 154 is set.Thus, set-point radiation source 30 closer.

More than, be illustrated at the method to set up of the some radiation source of embodiment 1.Under the state that is provided with a radiation source 30 like this, carry out the processing of correction unit 24 shown in Figure 1.Promptly, correction unit 24 according to roughly counted simultaneously from two detector module 14 of the paired annihilation gamma ray of a radiation source 30 separately each detection time and the distance between this two detector module 14, proofread and correct and be used to determine these two detector module 14 temporal information of detection time separately.And correction unit 24 is proofreaied and correct whole temporal information of a plurality of detector module 14.

Concrete condition is, when a plurality of diverse locations in detector cover 15 set gradually a some radiation source 30, correction unit 24 was proofreaied and correct two detector module 14 temporal information separately of roughly having counted simultaneously in the scope at the appointed time from the paired annihilation gamma ray of a radiation source 30.For example, the manager of PET device set-point radiation source 30 on keeper 151.And the manager for example proofreaies and correct with measuring via input part 21 inputs and begins request.And systems control division 27 is controlled, to carry out the processing of FE circuit 16 and coincidence circuit 17.In addition, when the correction of carrying out temporal information is handled, coincidence circuit 17 also can be only with the time window scope as search condition, generate count information simultaneously.That is, coincidence circuit 17 also can change search condition when the correction of carrying out temporal information is handled, when carrying out image reconstruction process.

If count information is stored simultaneously into 26a in the count information data successively near set-point, the position radiation source 30 of detector module 14-1 the time, then correction unit 24 begins to handle.Fig. 9 is the figure that is used to illustrate the correction unit of embodiment 1.

For example, among the count information data 26a, as illustrated in fig. 9 detector module 14-1 (ID:1) is stored as the while count information in the combination of time " T:t2 " detected metrical information in time " T:t1 " detected metrical information and detector module 14-14 (ID:14) at the same time.In addition, " P " shown in Figure 9 represents gamma-ray detection position, and " E " shown in Figure 9 represents gamma-ray energy.

At this moment, correction unit 24 uses the distance (with reference to D (1-14) shown in Figure 9) between detector module 14-1 and the detector module 14-14 to proofread and correct processing.That is, as illustrated in fig. 9, correction unit 24 is by " t1 " addition detection time " D (1-14)/c " to detector module 14-1, the correct detection time " T2 " of calculating detector module 14-14.In addition, " c " is gamma-ray speed, is the light velocity.

And, the time difference between the detection time " t2 " of correction unit 24 calculating " T2 " and detector module 14-14.The time difference that correction unit 24 calculates becomes the error with the temporal information of the temporal information of the detector module 14-1 detector module 14-14 for as benchmark the time.Therefore, correction unit 24 is used the time difference that calculates, the temporal information of calibration detector module 14-1 and detector module 14-14.Concrete condition is, correction unit 24 with the temporal information of detector module 14-1 as the relative datum value, the temporal information of calibration detector module 14-14.

Like this, when count information stored while count information data 26a into when will make up with the metrical information of detector module 14-1, correction unit 24 was just carried out the correction of two temporal informations between the detector module 14.

And the manager of PET device for example sets gradually a radiation source 30 according to the order of keeper 152,153,154.Thus, correction unit 24 is carried out the correction of temporal information respectively in 4 places.That is, correction unit 24 as the relative datum value, is proofreaied and correct the temporal information that becomes with the detector module 14 of the output source of the metrical information of the metrical information combination of detector module 14-10 with the temporal information of detector module 14-10.In addition, correction unit 24 as the relative datum value, is proofreaied and correct the temporal information that becomes with the detector module 14 of the output source of the metrical information of the metrical information combination of detector module 14-19 with the temporal information of detector module 14-19.In addition, correction unit 24 as the relative datum value, is proofreaied and correct the temporal information that becomes with the detector module 14 of the output source of the metrical information of the metrical information combination of detector module 14-28 with the temporal information of detector module 14-28.

In addition, correction unit 24 for example also can be passed through the control based on the systems control division 27 of gerentocratic setting, and count information is as process object when only will comprise the metrical information that is in the detector module 14 in the recoverable scope.Perhaps, correction unit 24 for example also can be by the control based on the systems control division 27 of gerentocratic setting, and count information is also as process object when will comprise the metrical information of the detector module 14 beyond the recoverable scope.

Like this, when setting gradually a some radiation source 30 at diverse location, correction unit 24 just closely the temporal information of the detector module 14 of set-point radiation source 30 proofread and correct the temporal information of each detector module 14 as the relative datum value.And, respectively proofread and correct processing when finishing when what the some radiation source 30 at 4 places was provided with the position, correction unit 24 is proofreaied and correct whole temporal information of a plurality of detector module 14.As mentioned above, at each the position repetition is set in each part that the detector module 14 of position recoverable temporal information is set.Therefore, correction unit 24 for example with the temporal information of detector module 14-1 as absolute standard value (for example " 0 "), the temporal information of the detector module 14 beyond the calibration detector module 14-1.

For example, correction unit 24 uses temporal information with detector module 14-1 as the relative datum value and the temporal information of corrected detector module 14-24 and with poor as the relative datum value and between the temporal information of corrected detector module 14-24 of the temporal information of detector module 14-10, and proofreading and correct will " temporal information of detector module 14-10 as the relative datum value and the temporal information of corrected each detector module 14 ".Similarly, correction unit 24 is proofreaied and correct temporal information with detector module 14-19 as the relative datum value and the temporal information of corrected each detector module 14 with the temporal information of detector module 14-1 as the absolute standard value.Similarly, correction unit 24 is also proofreaied and correct temporal information with detector module 14-28 as the relative datum value and the temporal information of corrected each detector module 14.Thus, the temporal information of correction unit 24 decision detector module 14 beyond the detector module 14-1 during as the absolute standard value with the temporal information of detector module 14-1.

And correction unit 24 will be proofreaied and correct the result and be stored among the time information data 26b shown in Figure 1.Figure 10 is the figure that is used to illustrate the time information data of embodiment 1.

For example, as shown in figure 10, as the result of correction unit 24, when the temporal information with detector module 14-1 (ID:1) was made as " 0 ", time information data 26b was stored as " Δ t2 " with the temporal information of the detector module 14 of " ID:2 ".Similarly, as shown in figure 10, time information data 26b is stored as " Δ t3 " with the temporal information of the detector module 14 of " ID:3 ", with ID:4 " the temporal information of detector module 14 be stored as " Δ t4 ".

And, when via input part 21 when the operator has accepted the photography request of PET image (TOF-PET image) of subject, control figure is as reconstruction portion 25 as described below for systems control division 27, and above-mentioned subject by the material of positron emission nucleic sign (has for example been thrown in ¹⁸F sign deoxyglucose medicaments such as (deoxyglucose)).

That is, image reconstruction portion 25 use according to by correction unit 24 corrected a plurality of detectors 14 separately temporal information and the time difference of each detection time of corrected paired annihilation gamma ray is rebuild the TOF-PET image of subject.Figure 11 is the figure that is used to illustrate the image reconstruction portion of embodiment 1.

Concrete condition is that the temporal information after the correction that image reconstruction portion stores among the information data 26b for 25 service time is revised count information when storing among the while count information data 26a.

For example, in an example shown in Figure 11, storage count information the time from the metrical information " P:P1_1, E:E1_1, T:T1_1 " of the output of the detector module 1 of " ID:1 " with from the metrical information " P:P2_2, E:E2_2, T:T2_2 " of detector module 14 outputs of " ID:2 ".At this moment, image reconstruction portion 25 obtains the temporal information " Δ t2 " of the detector module 14 of the temporal information " 0 " of detector module 14 of " DI:1 " and " DI:2 " from while count information data 26a.And as illustrated in fig. 11, image reconstruction portion 25 does not revise " T:T1_1 " and " T:T2_2 " is modified to " T:T2_2+ Δ t2 ".

In addition, in an example shown in Figure 11, storage count information the time from the metrical information " P:P10_2, E:E10_2, T:T10_2 " of the output of the detector module 14 of " ID:10 " with from the metrical information " P:P3_2, E:E3_2, T:T3_2 " of detector module 14 outputs of " ID:3 ".At this moment, image reconstruction portion 25 obtains the temporal information " Δ t3 " of the detector module 14 of the temporal information " Δ t10 " of the detector module 14 of " ID:10 " and " ID:3 " from while count information data 26a.And as shown in figure 11, image reconstruction portion 25 is modified to " T:T10_2+ Δ t10 " with " T:T10_2 ", " T:T3_2 " is modified to " T:T3_2+ Δ t3 ".

In addition, in an example shown in Figure 11, storage count information the time from the metrical information " P:P8_3, E:E8_3, T:T8_3 " of the output of the detector module 14 of " ID:8 " with from the metrical information " P:P20_3, E:E20_3, T:T20_3 " of the output of the detector module 14 of " ID:20 ".At this moment, image reconstruction portion 25 obtains the temporal information " Δ t20 " of the detector module 14 of the temporal information " Δ t8 " of the detector module 14 of " ID:8 " and " ID:20 " from the while count information.And as shown in figure 11, image reconstruction portion 25 is modified to " T:T8_3+ Δ t8 " with " T:T8_3 ", " T:T20_3 " is modified to " T:T20_3+ Δ t20 ".

Then, image reconstruction portion 25 uses count information when having revised detection time, rebuilds the TOF-PET image.

It is in addition, above-mentioned that the situation of the correcting process of count information is illustrated at undertaken simultaneously by image reconstruction portion 25.But embodiment 1 also carries out the situation of the correcting process of count information simultaneously by correction unit 24 or systems control division 27.Perhaps, embodiment 1 also can be that the count information of FE circuit information data 26b 16 service time having been revised the detection time of each detector module 14 outputs to the situation of coincidence circuit 17 when handling the dateout of each detector module 14.At this moment, because be according to temporal information and revised data the detection time of count information when generating by coincidence circuit 17, so image reconstruction portion 25 former states ground uses, and count information carries out the reconstruction of TOF-PET image when storing among the while count information data 26a.

In addition, above-mentionedly describe at the situation that correction unit 24 is set in control station device 20.But embodiment 1 also can be the situation that correction unit 24 is set in pallet device 10.At this, preferably when 16 service time, information data 26b revised the detection time of each detector module 14, correction unit 24 is set in pallet device 10, and in pallet device 10, time information data 26b is set also at the FE circuit.No matter under any situation, count information when image reconstruction portion 25 uses and revised detection time according to the result of correction unit 24 is rebuild the TOF-PET image.

In addition, in embodiment 1, carry out the correction of temporal information by setting gradually a radiation source 30 in a plurality of different positions.Therefore, the PET device of present embodiment 1 also can possess the pointer that the position is set of indication point radiation source 30, so that the manager can confirm the position that is provided with of a radiation source 30.

In addition, in embodiment 1, be illustrated at the situation that sets gradually a radiation source 30 in a plurality of different positions.But embodiment 1 also can be the situation that a plurality of somes radiation sources 30 once are set in a plurality of different positions.At this moment, also can proofread and correct the temporal information of all detector module 14.Wherein, for fear of as the random event of count information generation simultaneously, preferably set gradually a radiation source 30 at a plurality of diverse locations.

Secondly, use Figure 12 and Figure 13, describe at the handling process of the PET device of embodiment 1.Figure 12 is the flow chart that is used to illustrate that the correction of the PET device of embodiment 1 is handled, and Figure 13 is the flow chart of image reconstruction process that is used to illustrate the PET device of embodiment 1.

Whether as shown in figure 12, the PET device of embodiment 1 has in setting under the state of a radiation source 30, judge to have been accepted to proofread and correct with measuring from the manager by input part 21 to begin request (step (step) S101) there.At this, not proofread and correct with measuring (step S101 is for negative) when beginning to ask accepting, PET device becomes holding state.

On the other hand, proofread and correct with measuring when beginning to ask (step S101 for certainly) having accepted, by the control of systems control division 27, coincidence circuit 17 uses the data of FE circuit 16 outputs, generates while count information (step S102).

Then, correction unit 24 is according to becoming each information correction time detection time (step S103) of two detector module 14 of the output source of count information simultaneously.That is, as shown in Figure 9, correction unit 24 is used the distance between two detector module 14, proofreaies and correct the temporal information of these two detector module 14.

Then, correction unit 24 judges whether proofreaied and correct the temporal information (step S104) of having finished the detector module 14 in the recoverable scope.At this, when not proofreading and correct the temporal information of finishing the detector module 14 in the recoverable scope (step S104 is for negating), correction unit 24 is back to step S103, has used the correction of untreated while count information to handle.

On the other hand, when proofreading and correct the temporal information of having finished the detector module 14 in the recoverable scope (step S104 is for affirming), systems control division 27 judges whether accepted correction with measuring processing ending request (step S105).At this, when not accepting correction with measurement processing ending request (step S105 is for negative), systems control division 27 is back to step S101, under the state of different set-point, position radiation sources 30, judges that whether having accepted correction begins request with measurement.

On the other hand, when having accepted correction (step S105 is for affirming) with measurement processing ending request, correction unit 24 is proofreaied and correct the temporal information of all detector module 14, and the temporal information after will proofreading and correct stores (step S106) among the time information data 26b, end process into.In addition, the correction of above-mentioned temporal information is handled when PET device is dispatched from the factory, is carried out by the manager when PET device is made regular check on.

And the PET device information data service time 26b of embodiment 1 carries out the reconstruction process of TOF-PET image.That is, as shown in figure 13, the PET device of embodiment 1 is judged the photography request (step S201) of whether having been accepted PET image (TOF-PET image) by input part 21 from the operator there.At this, when not accepting the photography request (step S201 is for negating), PET device becomes holding state.

On the other hand, when having accepted the photography request (step S201 is for affirming), by the control of systems control division 27, coincidence circuit 17 uses the data of FE circuit 16 outputs to generate count information (step S202) simultaneously.

And image reconstruction portion 25 is by the control of systems control division 27, according to the detection time (step S203 is with reference to Figure 11) of the temporal information correction while count information after proofreading and correct.

Then, image reconstruction portion 25 count information when having revised detection time is rebuild PET image (TOF-PET image) (step S204), end process.

As mentioned above, in embodiment 1, in detector cover 15 or installing under the state that is equipped with the some radiation source 30 that comprises the positron emission nucleic everybody of a plurality of detector module on the detector cover, carry out the correction of temporal information and handle near regulation.Promptly, correction unit 24 is used to determine these two detector module 14 temporal information of detection time separately according to roughly having counted simultaneously to proofread and correct from each detection times of two detector module 14 of the paired annihilation gamma ray of a radiation source 30 and the distance between this two detector module 14, thereby proofreaies and correct whole temporal information of a plurality of detector module 14.

And, when the subject of the material of having thrown in positron emission nucleic sign is photographed, image reconstruction portion 25 use according to by correction unit 24 corrected a plurality of detector module 14 separately temporal information and the time difference of corrected paired annihilation gamma ray detection time is separately rebuild the PET image of subject.

Therefore, in embodiment 1,, and then the position will be set be made as a plurality ofly, can enlist the services of the combination of the gauged detector module 14 that can carry out temporal information only by near set-point radiation source 30 detector module 14.That is, in embodiment 1, can high accuracy and proofread and correct the temporal information of all detector module 14 easily.Consequently, in embodiment 1, can rebuild accurately and use gamma-ray detection time of poor image.

In addition, in embodiment 1, whenever a plurality of diverse locations in detector cover 15 or on the detector cover set gradually a radiation source 30, correction unit 24 is just proofreaied and correct two detector module 14 temporal information separately of roughly having counted paired annihilation gamma ray simultaneously.Therefore, present embodiment can be avoided generating random time as the while count information, can proofread and correct the temporal information of all detector module 14 reliably.

In addition, among the embodiment 1, adjust the position that is provided with of some radiation source 30, repeat with other detector module 14 that are provided with in other recoverable scopes of setting the position according to a radiation source 30 so that be at least one of detector module 14 in the recoverable scope of setting the position according to being provided with of a radiation source 30.Thus, in embodiment 1, not only in each correcting range accurately correction time information, and can proofread and correct the temporal information of all detector module 14.Therefore, in embodiment 1, can proofread and correct to degree of precision the temporal information of all detector module 14.

But, in PET device, will be configured to cyclic a plurality of detector module 14 in the mode on every side of surrounding subject P and dispose multiple row along the axon direction of subject P further, thereby can collect count information simultaneously three-dimensionally.At this moment, also can be arranged near the detector module 14 some radiation source 30, proofread and correct the temporal information of all detector module 14 by use.That is, the recoverable scope is not limited to be set in as shown in Figure 6 by situation about being configured in the face that cyclic a plurality of detector module 14 forms.Figure 14 is the figure that is used to illustrate the variation of recoverable scope.

That is, as shown in figure 14, it is the center that the recoverable scope also can be set to be arranged near the detector module 14 some radiation sources 30, along the three-dimensional situation of the axon direction of subject P.As shown in figure 14, by the set positions recoverable scope that is provided with at each some radiation source 30, even collect count information simultaneously three-dimensionally, the temporal information that correction unit 24 also can all detector module 14 of high-precision correction.

But, nearby having in the detector module 14 of set-point radiation source 30, gamma-ray counting rate increases.When counting rate increases, in FE circuit 16, in turn import the analog waveform data midway in calculation process.That is, in FE circuit 16, become the data stacking (pile up) of process object, can't collect the count results of having separated from each gamma-ray light.

Therefore, embodiment 1 also can constitute the situation of configuration heavy metal between the detector module 14 of a radiation source 30 and points of proximity radiation source 30.Figure 15 is the figure that is used to illustrate the variation of the embodiment relevant with putting being provided with of radiation source 1.

Concrete condition is, in this variation, and in the inside of each keeper (with reference to Fig. 8 A or Fig. 8 B) of set-point radiation source 30, as shown in figure 15, the heavy metal 16 that constitutes by high density materials such as ferrum, lead in position configuration near detector module 14.For example, in this variation, in the inside of keeper 15, configuration has for example ferrum of the thickness about 3cm.By configuration heavy metal 16, counting rate is descended.In this variation, though near detector module 14 set-point radiation source 30, also can avoid the generation of " pile up (pile up) ", can collect count results effectively.

In embodiment 2, describe at the situation of using the some radiation source different to calibrate the temporal information of all detector module 14 with embodiment 1.In addition, the PET device of embodiment 2 constitutes identical with the PET device of using the said clear embodiment 1 of Fig. 1.

In embodiment 2, in order to calibrate the temporal information of all detector module 14, in detector, the optional position in the scope of being surrounded by a plurality of detector module 14 is provided with and comprises the some radiation source that at least a portion is scattered the positron emission nucleic of body encirclement.Concrete condition is in embodiment 2, the some radiation source of the positron emission nucleic that is scattered the body encirclement around comprising to be set.Figure 16 is the figure that is used to illustrate the some radiation source that embodiment 2 uses.

That is, as shown in figure 16, the some radiation source 31 that embodiment 2 uses is formed by the scattering object 31b around object 31a that comprises the positron emission nucleic and the covering object 31a.For example, scattering object 31b is a high desnity metal etc.Can be by adjusting the thickness of scattering object 31b, the gamma-ray ratio of adjusting the gamma-rays launched from a radiation source 31 no scatterings ground and launching after a radiation source 31 scatterings.

The point radiation source 31 that covers object 31a with scattering object 31b similarly, is set in the FOV with the some radiation source (with reference to the some radiation source 30 of Fig. 3) that uses in the past.For example, some radiation source 31 is set at the center of photography mouth.Figure 17 is used for illustrating the figure that can be detected as the combination of the gamma-ray detector module of pair annihilation at embodiment 2.

Owing to pass through scattering object 31b scattering from the paired annihilation gamma ray of a radiation source 31 emissions, therefore as shown in figure 17, can passing through not, two detector module on LOR 14 detect.In addition, the situation that the paired annihilation gamma ray of launching from a radiation source 31 also exists both sides not to be launched with all having scattering, the paired annihilation gamma ray of this moment detects by two detector module 14 on the LOR.That is, in present embodiment 2,, can in whole combination of a plurality of detector module 14, carry out the correction of temporal information by using the some radiation source 31 that covers object 31a with scattering object 31b.In addition, the position of set-point radiation source 31 can be arranged on the optional position in the scope that a plurality of detector module 14 are surrounded.

More than, be illustrated at the some radiation source 31 of embodiment 2.Under the state that is provided with a radiation source 31 in this wise, carry out the processing of correction unit 24 shown in Figure 1.Promptly, the correction unit 24 of embodiment 2 is used to determine these two detector module 14 temporal information of detection time separately according to roughly having counted simultaneously from two detector module 14 detection time, the position of these two detector module 14 and position of some radiation source 31 separately of the paired annihilation gamma ray of a radiation source 31 emissions, having proofreaied and correct.Thus, the correction unit 24 of embodiment 2 is proofreaied and correct whole temporal information of a plurality of detector module 14.

Concrete condition is, the correction unit 24 of embodiment 2, at official hour window ranges inside counting proofread and correct from two detector module 14 temporal information separately of the paired annihilation gamma ray of a radiation source 31.At first, the manager set-point radiation source 31 of the PET device of embodiment 2, and proofread and correct with measuring via input part 21 input and to begin to ask.Then, systems control division 27 is controlled, to carry out the processing of FE circuit 16 and coincidence circuit 17.For example, when the correction of carrying out temporal information was handled, 17 of the coincidence circuits of embodiment 2 as search condition, generated count information simultaneously with the time window scope.That is, coincidence circuit 17 also can change testing conditions when the correction of carrying out temporal information is handled and when carrying out image reconstruction process.

When passing through this control, when count information stored among the while count information data 26a successively simultaneously, correction unit 24 began to handle.Figure 18 is the figure that is used to illustrate the correction unit of embodiment 2.

For example, be located among the while count information data 26a, as shown in figure 18, as the detector module 14 of while count information storage " ID:2 " in the combination of the detector module 14 of time " T:t1 " detected metrical information and " ID:16 " in time " T:t2 " detected metrical information.In addition, " P " shown in Figure 180 represents gamma-ray detection position, and " E " shown in Figure 180 represents gamma-ray energy.

At this moment, correction unit 24 uses the detector module 14 of " ID:2 " and the detector module 14 of the distance (D2) between the some radiation source 31 and " ID:16 " and the distance (D16) between the some radiation source 31 to proofread and correct processing.That is, as shown in figure 18, correction unit 24 judges whether " t1-t2 " equals " (D2/c)-(D16/c) ".Wherein, " c " is gamma-ray speed, is the light velocity.

At this, when " t1-t2 " equals " (D2/c)-(D16/c) ", judge that " ID:2 " and " ID:16 " these two detector module 14 detection times separately is to measure according to correct temporal information.But " t1-t2 " and " (D2/c)-(D16/c) " not simultaneously, correction unit 24 is proofreaied and correct the temporal information of the detector module 14 of the temporal information of the detector module 14 of " ID:2 " and " ID:16 ".That is, correction unit 24 is used " t1-t2 " and " (D2/c)-(D16/c) poor, the temporal information of detection module 14 that for example will " ID:2 " be as the relative datum value, the temporal information of the detector module 14 of correction " ID:16 ".

Like this, when storing into while information among the while count information data 26a, correction unit 24 is just carried out the correction of two temporal informations between the detector module 14.

And, correction unit 24 for example with the temporal information of the detector module 14 of " ID:1 " as absolute standard value (for example " 0 "), the temporal information of the detector module 14 beyond the detector module 14 of " ID:1 " is proofreaied and correct.Thus, correction unit 24 is proofreaied and correct the temporal information of all detector module 14.

And correction unit 24 will be proofreaied and correct the result and be stored among the time information data 26b shown in Figure 1.Figure 19 is the figure that is used to illustrate the time information data of embodiment 2.

For example, as shown in figure 19,, be 0 o'clock in the temporal information of establishing detector module 14-1 (ID:1) as the result of the correction unit 24 of embodiment 2, time information data 26b is stored as " Δ t2 " with the temporal information of the detector module 14 of " ID:2 ".Similarly, as shown in Figure 7, time information data 26b is stored as " Δ t3 " with the temporal information of the detector module 14 of " ID:3 ", with the temporal information " Δ t4 " of the detector module 14 of " ID:4 ".

And, when the photography request of the PET image (TOF-PET image) of having accepted subject from the operator via input part 21, control figure is as the reconstruction process of reconstruction portion 25 like that as described below for systems control division 27, and wherein above-mentioned subject (has for example been thrown in the material that indicated by the positron emission nucleic ¹⁸F indicates medicaments such as deoxyglucose).

That is, similarly to Example 1, image reconstruction portion 25 according to use by correction unit 24 gauged a plurality of detector module 14 separately temporal information and the time difference of each detection time of corrected paired annihilation gamma ray is rebuild the TOF-PET image of subject.Figure 20 is the figure that is used to illustrate the image reconstruction portion of embodiment 2.

Concrete condition is, count information when storing among the while count information data 26a of the temporal information after the correction that image reconstruction portion stores among the information data 26b for 25 service time is revised.

For example, in an example shown in Figure 20, storage count information the time from the metrical information " P:P1_1, E:E1_1, T:T1_1 " of the output of the detector module 14 of " ID:1 " with from the output metrical information " P:P2_2; E:E2_2, T:T2_2 " of the detector module 14 of " ID:2 ".At this moment, image reconstruction portion 25 obtains the temporal information " Δ t2 " of the detector module 14 of the temporal information " 0 " of detector module 14 of " ID:1 " and " ID:2 " from while count information data 26a.Then, as illustrated in fig. 8, " T:T1_1 " do not revise in image reconstruction portion 25, and " T:T2_2 " is modified to " T:T2_2+ Δ t2 ".

In addition, in an example shown in Figure 20, storage count information the time from the metrical information " P:P10_2, E:E10_2, T:T10_2 " of the output of the detector module 14 of " ID:10 " with from the metrical information " P:P3_2, E:E3_2, T:T3_2 " of the output of the detector module 14 of " ID:3 ".At this moment, image reconstruction portion 25 obtains the temporal information " Δ t3 " of the detector module 14 of the temporal information " Δ t10 " of the detector module 14 of " ID:10 " and " ID:3 " from while count information 26a.And as illustrated in fig. 20, image reconstruction portion 25 is modified to " T:T10_2+ Δ t10 " with " T:T10_2 ", " T:T3_2 " is modified to " T:T3_2+ Δ t3 ".

In addition, in an example shown in Figure 20, storage count information the time from the metrical information " P:P8_3, E:E8_3, T:T8_3 " of the output of the detector module 14 of " ID:8 " with from the metrical information " P:P20_3, E:E20_3, T:T20_3 " of the output of the detector module 14 of " ID:20 ".At this moment, image reconstruction portion 25 obtains the temporal information " Δ t20 " of the detector module 14 of the temporal information " Δ t8 " of the detector module 14 of " ID:8 " and " ID:20 " from while count information data 26a.And as illustrated in fig. 8, image reconstruction portion 25 is modified to " T:T8_3+ Δ t8 " with " T:T83 ", and " T:T20_3 " is modified to " T:T20_3+t20 ".

It is in addition, above-mentioned that the situation of the correcting process of count information is illustrated to undertaken simultaneously by image reconstruction portion 25.But present embodiment 2 also can be to carry out the situation of the correcting process of count information simultaneously by correction unit 24 or systems control division 27.Perhaps, present embodiment 2 also can be when handling the dateout of each detector module 14, and the count information that FE circuit information data 26b 16 service time has been revised the detection time of each detector module 14 outputs to the situation of coincidence circuit 17.At this moment, because be according to temporal information and revised data the detection time of count information when generating by coincidence circuit 17, so image reconstruction portion 25 former states ground uses, and count information carries out the reconstruction of TOF-PET image when storing among the while count information data 26a.

In addition, above-mentioned the situation that correction unit 24 is set in control station device 20 is described.But present embodiment 2 also can be the situation that correction unit 24 is set in pallet device 10.When FE circuit information data 26b 16 service time revised the detection time of each detector module 14, correction unit 24 preferably is set in pallet device 10, and time information data 26b is set in pallet device 10.No matter under any situation, count information when image reconstruction portion 25 has all used by the result correction of correction unit 24 detection time is rebuild the TOF-PET image.

Next, use Figure 21 and Figure 22 that the handling process of the PET device of embodiment 2 is described.Figure 21 is the flow chart that is used to illustrate that the correction of the PET device of embodiment 2 is handled, and Figure 22 is the flow chart of image reconstruction process that is used to illustrate the PET device of embodiment 2.

As shown in figure 21, whether the PET device of embodiment 2 is judged to have been accepted to proofread and correct with measuring from manager person by input part 21 to begin request (step S201) under the state that is provided with a radiation source 31.At this, not proofread and correct with measuring (step S201 is for negative) when beginning to ask accepting, PET device becomes holding state.

On the other hand, proofread and correct with measuring when beginning to ask (step S201 for certainly) having accepted, by the control of systems control division 27, coincidence circuit 17 uses the data of FE circuit 16 outputs, generates while count information (step S202).

And correction unit 24 is according to becoming two detector module 14 information correction time detection time (step S203) separately of the output source of count information simultaneously.That is, as shown in figure 18, correction unit 24 uses two detector module 14 separately and the distance between the radiation source 31, and the temporal information of these two detector module 14 is proofreaied and correct.

Then, correction unit 24 judges whether proofreaied and correct temporal information (step S204) in the combination of all detector module 14.At this,, used the correction of untreated while count information to handle in that correction unit 24 is not back to step S203 during information (step S204 is for negating) correction time in the combination of all detector module 14.

On the other hand, when in the combination of all detector module 14, having proofreaied and correct temporal information (step S204 is for affirming), correction unit 24 is proofreaied and correct the temporal information of all detector module 14, and stores gauged temporal information into time information data 26b (step S205), end process.In addition, the correction of above-mentioned temporal information is handled when PET device is dispatched from the factory, when PET device is made regular check on, and is carried out by the manager.

And the PET device information data service time 26b of present embodiment 2 carries out the reconstruction process of TOF-PET image.That is, as shown in figure 22, the PET device of present embodiment 2 is judged the photography request (step S301) of whether having been accepted PET image (TOF-PET image) by input part 21 from the operator.At this, when not accepting the photography request (step S301 is for negating), PET device becomes holding state.

On the other hand, when having accepted the photography request (step S301 is for affirming), by the control of systems control division 27, coincidence circuit 17 uses the data of FE circuit 16 outputs, generates count information (step S302) simultaneously.

And image reconstruction portion 25 is by the control of systems control division 27, according to the detection time (step S303 is with reference to Figure 20) of corrected temporal information correction while count information.

Then, image reconstruction portion 25 count information when having revised detection time is rebuild PET image (TOF-PET image) (step S304), end process.

As mentioned above, in present embodiment 2, correction unit 24 is according in having the detector of counting from a plurality of detector module 14 of gamma-ray light, optional position in the scope that a plurality of detector module 14 are surrounded is provided with two detector module 14 detection time separately of roughly having counted paired annihilation gamma ray simultaneously under the state of the some radiation source 31 that comprises the positron emission nucleic that is scattered body 31b encirclement on every side, the position of the position of these two detector module 14 and some radiation source 31, correction is used to determine the temporal information of each detection time of these two detector module 14, thereby proofreaies and correct whole temporal information of a plurality of detector module 14.When the subject of having thrown in the material that is identified by the positron emission nucleic is photographed, image reconstruction portion 25 uses the time difference according to each detection time of the paired annihilation gamma ray of having been revised by correction unit 24 corrected a plurality of detector module 14 temporal information separately, rebuilds the TOF-PET image of subject.

Therefore, in present embodiment 2, only use the some radiation source 31 that is scattered the positron emission nucleic of body 31b encirclement around comprising, can enlist the services of the combination of the gauged detector module 14 that can carry out time information data.That is, in present embodiment 2, can high accuracy and proofread and correct the temporal information of all detector module 14 easily.Consequently, in present embodiment 2, can rebuild accurately and use gamma-ray detection time of poor image.

In embodiment 3, the situation of count information describes when using Figure 23 to use in the temporal information correction being chosen in.Figure 23 is the figure that is used to illustrate the correction unit of embodiment 3.

It is identical that the PET device of embodiment 3 constitutes the PET device relevant with embodiment 2.But, the correction unit 24 of embodiment 3 is based on the gamma-ray energy that calculates according to the count results of each detector module 14, use two detector module 14 detection time separately of roughly having counted paired annihilation gamma ray simultaneously, proofread and correct these two detector module 14 temporal information separately, the gamma-rays that wherein above-mentioned paired annihilation gamma ray is at least one side is not scattered the gamma-rays of body 31b scattering ground emission.Promptly, in having the detector of counting from a plurality of detector module 14 of gamma-ray light, optional position in the scope of surrounding with a plurality of detector module 14 is provided with under the state of the some radiation source 31 that comprises the positron emission nucleic that is scattered body 31b encirclement on every side, the gamma-ray energy that the correction unit 24 of embodiment 3 calculates based on the count results according to each detector module 14, determine roughly to have counted simultaneously two detector module 14 of paired annihilation gamma ray, the gamma-rays that wherein above-mentioned paired annihilation gamma ray is at least one side not by scattering object 31b scattering the gamma-rays that is launched.And, the correction unit 24 of embodiment 3 is according to each detection time of two detector module 14 determining, the position of these two detector module 14 determining and the position of some radiation source 31, proofreaies and correct the temporal information of each detection time that is used to determine these two detector module.Thus, the correction unit 24 of embodiment 3 is proofreaied and correct whole temporal information of a plurality of detector module 14.

In other words, the correction unit 24 of embodiment 3 is based on the gamma-ray energy value that calculates according to the count results of each detector module 14, count information and count information when having counted the paired annihilation gamma ray that no scattering one side of a side has scattering when having selected to count both sides and all do not have the paired annihilation gamma ray of scattering.Thus, the correction unit 24 of embodiment 3 is got rid of count information when to detect both sides all be the paired annihilation gamma ray of scattered ray from the process object data of time adjustment.

For example, the gamma-ray energy after the scattering is made as " E _s", the gamma-ray energy of (no scattering) before the scattering is made as " E _i", with " m " be made as electronics quality, " θ " is made as gamma-ray angle of scattering, " c " is made as the light velocity, then the gamma-ray energy " E after the scattering _s" by calculating with following formula (1).

E_{s} = \frac{{mc}^{2} E_{i}}{mc} \cdot \cdot \cdot (1)

For example, by use formula (1), be " 511kev " if establish " Ei ", " Es " when angle of scattering is " 45 ° " then is " 395kev ".That is, gamma-rays is because the angle of scattering and degradedness.Therefore, the count results of scattered ray is because energy is little, so for example at the threshold measurement of service voltage value during detection time, certainty of measurement worsens.Therefore, preferred detection when to go out both sides all be the paired annihilation gamma ray of scattered ray the detection time of count information be not used for information correction time.

For example, as shown in figure 23, in the count information, the detector module 14 of establishing " ID:2 " is " e1 " at the energy of time " T:t1 " detected metrical information at the same time, and the detector module 14 of " ID:16 " is " e2 " at the energy of " T:t2 " detected metrical information.Therefore, correction unit 24 is according to two detector module 14 of the output source that becomes the count information that forms the while count information and the position of putting radiation source 31, and calculating angle of scattering is " 45 ° ".And correction unit 24 is calculated as " Es:365kev " with " angle of scattering: 45 ° " substitution formula (1).

And, as shown in figure 23, when " 511-a＜e1＜511+a " and " 395-b＜e2＜395+b " or when " 395-b＜e1＜395+b " and " 511-a＜e2＜511+a ", correction unit 24 is used count information the time shown in Figure 23, carries out the correction of temporal information of the detector module 14 of " ID:2 " and " ID:16 ".That is, the gamma-rays roughly counted simultaneously as at least one side of correction unit 24 detector module 14 that is defined as " ID:2 " and " ID:16 " is the gamma-ray paired annihilation gamma ray that is scattered the emission of body 31b scattering ground.In addition, count information when being roughly " 0 ° " at the calculating angle of scattering, when the energy both sides were " 511-a＜e1＜511+a ", correction unit 24 was carried out the correction of temporal information and is handled.In addition, " a " and " b " shown in Figure 11 can be set arbitrarily by the manager of PET device.

Thus, correction unit 24 got rid of detect the paired annihilation gamma ray that both sides are scattered ray in behind the count information, proofread and correct the temporal information of all detector module 14.

Secondly, use Figure 24 that the handling process of the PET device of present embodiment 3 is described.Figure 24 is the flow chart that is used to illustrate that the correction of the PET device of embodiment 3 is handled.In addition, the image reconstruction process of the PET device of the embodiment 2 that the image reconstruction process of the PET device of embodiment 3 is illustrated with using Figure 22 is identical, therefore omits explanation.

Whether as shown in figure 24, the PET device of embodiment 3 is judged is had under the state of a radiation source 31 in setting, accepted to proofread and correct with measuring from the manager by input part 21 to begin request (step S401).At this, not proofread and correct with measuring (step S401 is for negative) when beginning to ask accepting, PET device becomes holding state.

On the other hand, proofread and correct with measuring when beginning to ask (step S401 for certainly) having accepted, by the control of systems control division 27, coincidence circuit 17 uses the data of FE circuit 16 outputs, generates while count information (step S402).

And, count information (step S403) when the energy window scope that correction unit 24 selects through type (1) to set is interior.That is, correction unit 24 has selected to count all count informations and counted the not count information paired annihilation gamma ray of scattering one side's scattering time of a side paired annihilation gamma ray of scattering time not of both sides.

Then, correction unit 24 is according to each information correction time detection time (step S404) of two detector module 14 of the output source that becomes selected while count information.

And correction unit 24 judges whether all proofreaied and correct temporal information (step S405) in the combination of all detector module 14.At this,, used the correction of untreated while count information to handle when correction unit 24 is not back to step S403 during information (step S405 is for negating) correction time in the combination of all detector module 14.

On the other hand, when in the combination of all detector module 14, all having proofreaied and correct temporal information (step S405 is for affirming), correction unit 24 is proofreaied and correct the temporal information of all detector module 14, and the temporal information after will proofreading and correct stores (step S406) among the time information data 26b, end process into.

As mentioned above, in present embodiment 3,, proofread and correct the temporal information of all detector module 14 owing to get rid of the detection time of count information when to detect both sides all be the paired annihilation gamma ray of scattered ray, thus more accurately correction time information.Consequently, in present embodiment 3, more high accuracy is rebuild and has been used gamma-ray detection time of poor image.

In addition, in the foregoing

description

2 and 3, the situation that forms a radiation source 31 at the entire circumference that covers object 31a by scattering object 31b is illustrated.But embodiment 2 and the 3 point radiation sources 31 that use also can form by the part of scattering object 31b covering object 31a.Figure 25 A and Figure 25 B are the figure that is used to illustrate the variation of embodiment 2 and the 3 point radiation sources that use.

For example, shown in Figure 25 A, some radiation source 31 also can form by the latter half of scattering object 31b covering object 31a.Perhaps, shown in Figure 25 B, some radiation source 31 also can form by the many places of scattering object 31b covering object 31a.That is, so long as by making the paired annihilation gamma ray part scattering from a radiation source 31 emissions, can generate count information simultaneously in the combination of all detector module 14, then the figure by scattering object 31b covering object 3a can change arbitrarily.

In addition, even use the some radiation source 31 that illustrated at

embodiment

2 and 3, even collect count information simultaneously three-dimensionally, correction unit 24 also can be proofreaied and correct the temporal information of all detector module 14 accurately.

In addition, present embodiment 1～3 illustrated nuclear medicine method can realize by carry out preprepared nuclear medicine program (program) in the computer of personal computer (personal computer), work station (workstation) etc.The nuclear medicine program can be distributed via the Internet networks (network) such as (internet).In addition, the nuclear medicine program also can be stored to computer-readable recording mediums such as hard disk (hard disk), floppy disk (FD:flexible disk), CD-ROM, MO, DVD, and by from storage medium, reading out execution by computer.

As described below, can rebuild the image that has used differ from gamma-ray detection time accurately according to embodiment 1～3.

Be illustrated at several embodiments of the present invention, these embodiments illustrate as an example, are not intended to limit scope of invention.These embodiments can be implemented by other variety of ways, in not breaking away from the main idea scope of invention, can carry out various omissions, displacement, change.These embodiments or its distortion be included in invention scope or main idea in the same, be included in the invention scope impartial of the interior record of patent request scope with it.

Also have, the combination according to disclosed a plurality of element that suits in the above-mentioned embodiment can form various inventions.For example: both can eliminate several elements of the whole elements that from embodiment, show, and can suitably make up the element in the different embodiments again.

Those skilled in the art expect other advantage and alter mode easily.Therefore, the present invention is not limited to the detail and the representational embodiment that illustrate and illustrate here with regard to its wideer aspect.Therefore, do not deviate from by appending claims with and the situation of the spirit and scope of the general inventive concept that limits of equivalent under, can carry out various modifications.

Claims

1. a nuclear medical imaging apparatus is characterized in that, comprising:

Detector has a plurality of detector module of counting from gamma-ray light;

Correction unit, according to installing each detection time of two detector module roughly having counted paired annihilation gamma ray under the state that is equipped with the some radiation source that comprises the positron emission nucleic simultaneously and the distance between this two detector module everybody of a plurality of detector module near regulation, correction is used to determine these two detector module temporal information of detection time separately, thereby proofreaies and correct whole temporal information of above-mentioned a plurality of detector module; And

Image reconstruction portion, when the subject of having thrown in the material that is identified by the positron emission nucleic is photographed, use the time difference of each detection time of paired annihilation gamma ray, rebuild the nuclear medical image of above-mentioned subject, be the detection time of having revised according to by the corrected above-mentioned a plurality of detector module of above-mentioned correction unit temporal informations separately each detection time of above-mentioned paired annihilation gamma ray.

2. nuclear medical imaging apparatus according to claim 1 is characterized in that:

When a plurality of diverse locations at above-mentioned detector set gradually above-mentioned some radiation source, above-mentioned correction unit was proofreaied and correct two detector module temporal information separately of roughly having counted paired annihilation gamma ray simultaneously.

3. nuclear medical imaging apparatus according to claim 2 is characterized in that:

So that be in according to above-mentioned some radiation source detector module in the scope of setting the position is set at least one the multiple mode of detector module in the scope of setting the position is set with being in according to other of above-mentioned some radiation source, adjust the position that is provided with of above-mentioned some radiation source.

4. nuclear medical imaging apparatus according to claim 1 is characterized in that, also comprises:

Heavy metal is configured between above-mentioned some radiation source and the detector module near this radiation source.

5. a nuclear medical imaging apparatus is characterized in that, comprising:

Detector has a plurality of detector module of counting from gamma-ray light;

Cover is taken in above-mentioned detector;

Correction unit, according in the above-mentioned cover or above-mentioned cover be provided with each detection time of two detector module roughly having counted paired annihilation gamma ray under the state of the some radiation source that comprises the positron emission nucleic that is configured near each position of a plurality of detector module of regulation simultaneously and the distance between this two detector module, correction is used to determine these two detector module temporal information of detection time separately, thereby proofreaies and correct whole temporal information of above-mentioned a plurality of detector module; And

6. nuclear medical imaging apparatus according to claim 5 is characterized in that, also comprises:

Keeper is arranged in the above-mentioned cover, takes in above-mentioned some radiation source.

7. nuclear medical imaging apparatus according to claim 5 is characterized in that:

When a plurality of diverse locations in above-mentioned cover or on the above-mentioned cover set gradually above-mentioned some radiation source, above-mentioned correction unit was proofreaied and correct two detector module temporal information separately of roughly having counted paired annihilation gamma ray simultaneously.

8. nuclear medical imaging apparatus according to claim 7 is characterized in that:

9. nuclear medical imaging apparatus according to claim 5 is characterized in that, also comprises:

10. a nuclear medicine method is characterized in that, comprising:

Correction unit is according to installing each detection time of two detector module roughly having counted paired annihilation gamma ray under the state that is equipped with the some radiation source that comprises the positron emission nucleic simultaneously and the distance between this two detector module near having counting from everybody of a plurality of detector module of the regulation of the detector of a plurality of detector module of gamma-ray light, correction is used to determine these two detector module temporal information of detection time separately, thereby proofreaies and correct whole temporal information of above-mentioned a plurality of detector module;

Image reconstruction portion is when photographing to the subject of having thrown in the material that is identified by the positron emission nucleic, use time difference, rebuild the nuclear medical image of above-mentioned subject according to each detection time of the paired annihilation gamma ray of having revised by the corrected above-mentioned a plurality of detector module of above-mentioned gauged step temporal information separately.

11. a nuclear medical imaging apparatus is characterized in that, comprising:

Detector has a plurality of detector module of counting from gamma-ray light;

Correction unit, optional position in the scope of surrounding with above-mentioned a plurality of detector module is provided with and comprises under the state of some radiation source that at least a portion is scattered the positron emission nucleic that body surrounds, the gamma-ray energy that calculates based on count results according to each detector module, determine roughly to have counted simultaneously two detector module of paired annihilation gamma ray, and according to each detection times of this two detector module determining, the position of two detector module should determining and the position of above-mentioned some radiation source, correction is used to determine these two detector module temporal information of detection time separately, thereby proofread and correct whole temporal information of above-mentioned a plurality of detector module, wherein at least one side's of above-mentioned paired annihilation gamma ray gamma-rays is not by the gamma-rays of above-mentioned scattering object scattering ground emission; And

12. nuclear medical imaging apparatus according to claim 11 is characterized in that:

Above-mentioned correction unit is used the relational expression that calculates the gamma-ray energy after the scattering according to the gamma-ray energy before the scattering and angle of scattering, determine roughly to have counted simultaneously two detector module of paired annihilation gamma ray, wherein at least one side's of above-mentioned paired annihilation gamma ray gamma-rays is not by the gamma-rays of above-mentioned scattering object scattering ground emission.

13. a nuclear medicine method is characterized in that, comprising:

In having the detector of counting from a plurality of detector module of gamma-ray light, optional position in the scope of surrounding with above-mentioned a plurality of detector module is provided with and comprises under the state of some radiation source that at least a portion is scattered the positron emission nucleic that body surrounds, the gamma-ray energy that correction unit calculates based on the count results according to each detector module, determine roughly to have counted simultaneously two detector module of paired annihilation gamma ray, and according to each detection times of this two detector module determining, the position of two detector module should determining and the position of above-mentioned some radiation source, correction is used to determine these two detector module temporal information of detection time separately, thereby proofread and correct whole temporal information of above-mentioned a plurality of detector module, wherein at least one side's of above-mentioned paired annihilation gamma ray gamma-rays is not by the gamma-rays of above-mentioned scattering object scattering ground emission;

When the subject of having thrown in the material that is identified by the positron emission nucleic is photographed, image reconstruction portion uses the time difference of each detection time of paired annihilation gamma ray, rebuild the nuclear medical image of above-mentioned subject, be the detection time of having revised according to by the corrected above-mentioned a plurality of detector module of above-mentioned gauged step temporal informations separately each detection time of above-mentioned paired annihilation gamma ray.

14. nuclear medicine method according to claim 13 is characterized in that: